Required practical 9 - Light Flashcards
Outline the basic steps of the practical
1) Draw a straight line and a line normal to it in the centre of the paper.
2) Place the block along the main line and shine the ray light at the position where the normal meets the block.
3) Mark with crosses the incoming, and any outgoing rays of light.
4) Turn lights on and measure the angles of incidence, reflection and refraction.
What tool should be used to help draw the normal line on the sheet of paper?
A set square or protractor to ensure that the line
is at a right angle to the main line.
What precautions should be taken to use the ray box safely?
- Don’t touch any metal parts since the box gets very hot when in operation.
- Switch off when not in use to prevent overheating.
What conditions are needed for this expoeriment?
Low lighting is needed so that the rays are visible.
What 3 angles should you measure after you have marked the lines on the paper? How?
- Angle of incidence.
- Angle of reflection.
- Angle of refraction.
Using a protractor.
Which angle is the angle of incidence?
The angle as measured between the incident (incoming) ray and the normal.
Which angle is the angle of reflection?
The angle as measured between the reflected ray and the normal.
What is the normal?
Any line perpendicular to the surface of the mirror/block.
How do you draw the refracted ray?
Connect the point where the ray entered the block and the point where the ray left the block on the other side with a straight line.
What does theory suggest about the angle of refraction for different materials?
It should be different for each material depending on its refractive index.
What does theory suggest about the angle of incidence and the angle of reflection?
The angle of incidence should be the same as the angle of reflection.
